Product data

4 Introduction

Thank you for choosing Morningstar for your PV control system needs. Morningstar prod-

ucts offer a wide range of networking, logging, data transfer, and custom setting capabili-

ties. Please review this document carefully and become familiar with all the networking/

communication options Morningstar products have to offer.

1.1 Communications Protocols

Various protocols are used by Morningstar products to either communicate between Morningstar

devices, or with a PC/other 3rd party hardware. A brief description of these protocols follow:

1.1.1 Morningstar MeterBus

MeterBus

Protocol is Morningstar’s proprietary messaging structure for communication be-

tween Morningstar products. This protocol is used for communications between controllers and

meters, controllers and Relay Drivers, and for other inter-product data transfer.

Morningstar products supporting this protocol feature RJ-11 ports. Physical connections between

MeterBus

devices are made using standard 4 or 6 conductor phone cords with RJ-11 connec-

tors. MeterBus

networks have a 15 device capability, a simple RJ-11 interface, and are easy to

setup and maintain.

Meter Hubs are used to network MeterBus

capable devices. Each network device is assigned a

unique MeterBus ID. In these networks, some devices supply power to the network, while others

receive power from the network.

For more information into the capabilities of MeterBus

and how to setup a MeterBus

network,

please refer to Section 3.

1.1.2 MODBUS

MODBUS

is an open and license-free protocol that is widely regarded as the de facto standard

in the industrial automation industry. There is an abundance of software and equipment available

that directly support MODBUS

. Additionally, sample source code for a variety of platforms is

readily available online. Morningstar’s free MSView PC software uses MODBUS

for all commu-

nications.

MODBUS

does not rely on any one physical communication interface; it works the same on all

physicalinterfaces.Eachdeviceisconguredtobeamasteroraslave.Mastersalways‘poll’or

start conversations on the network and either slaves or other masters can respond. Two modes

1.0 Introduction